The invention relates to an improved seat suspension assembly using a roller assembly and a channel or guide as part of the suspension system. Typically, seat suspensions use roller assemblies attached to shafts and that are adapted to travel in metal channels or guides having opposing guide surfaces on which the rollers cycle back and forth. In addition, the guides often act to limit the perpendicular movement of the roller with respect to the guide by positioning the guide surfaces in close proximity to the upper and lower most points on a roller. However, several competing design considerations play a role in the position of the guide surfaces with respect to the rollers.
First, any tolerance between the rollers and guides creates unwanted play in the suspension which results in undesirable movement in the seat. A reduced or zero tolerance, on the other hand, may result in a force which resists the movement of the roller in the guide as the suspension actuates. This results in friction that may unnecessarily wear the rollers and other components, and if the force is great enough, it may result in converting the rollers into slider blocks or even preventing the movement of the rollers altogether. Thus, there is a need in seat suspensions in which a press-fit like relationship between a roller and guide may be achieved to eliminate unwanted play without the attendant problems associated which sandwiching a roller between two opposingly located guide surfaces.